// Callback object
WPSLocationCallback callback = new WPSLocationCallback()
{
// What the application should do after it's done
public void done()
{
// after done() returns, you can make more WPS calls.

}

// What the application should do if an error occurs
public WPSContinuation handleError(WPSReturnCode error)
{
//handleWPSError(error); // you'll implement handleWPSError()

when you create a new project in eclipse you just add the wpsapi.jar in the same folder as your project. You can then use the skyhook technology. I have posted a working piece of sample code in the skyhook user group.